When you have no state (no local state or you just switched to a new env) and run `terraform state pull`, it would crash.
Removing the call to StateMeta.Env, so that it doesn't need an embedded Meta field. Embed Meta and StateMeta separately in all State commands.
Add Env and SetEnv methods to command.Meta to retrieve the current environment name inside any command. Make sure all calls to Backend.State contain an environment name, and make the package compile against the update backend package.